In oncologic patients adrenal insufficiency may result from infiltrati
on by the tumor, metastatic spread, chemotherapy or complications aris
ing from it. On many occasions symptoms of adrenal insufficiency are c
losely resembling complaints caused by the tumor itself Cortisol defic
iency can be made evident by a simple diagnostic procedure and substit
ution therapy is able to improve expectancy and quality of life in the
se patients.